Method And Device For Aiding The Piloting Of An Aircraft During A Final Approach Phase

ABSTRACT

Method and device for aiding the piloting of an aircraft during a final approach phase. 
     The device ( 1 ) comprises means ( 3 ) for automatically selecting an approach that will be used during the landing on an airport.

The present invention relates to a method and a device for aiding thepiloting of an aircraft, particularly a transport aircraft, during anapproach final phase for the landing on an airport.

To implement an approach final phase on an airport, the crew of anaircraft, particularly of a transport aircraft, has to indicate to theon-board systems the particular final approach that has to be followed,amongst a plurality of different approaches being possible. The cockpitsof the aircrafts include a flight management system, of the <<FMS>>(<<Flight Management System>>) type, that represents a man-machineinterface generally allowing the crew to select the final approach. Whensuch selection is performed, the on-board systems automaticallycoordinate to allow the aircraft to fly according to the selected finalapproach.

It is known that the air-traffic controllers can recommend a specificapproach, particularly that use the most efficient approach aid meansprovided on board the aircraft or the one that is available according toplanned maintenance and traffic actions, as well as meteorology. Thepilot can select an approach different from that recommended, forinstance if an on-board equipment the use of which is necessary for thisrecommended approach is out of service or if he/she wants to trainhim/herself to perform an other approach (with the proviso that themeteorological conditions allow it).

To select a final approach, the crew has to consult the usual approachcharts (paper or electronic format). On these approach charts, the finalapproaches are characterized by their type (precision, no precision),the guiding means being used, and the minimal decision heights beingallowed. The selection of a final approach also relies on the aircraftability to technically implement such approach, that is the equipmentprovided on board the aircraft, their running state, . . .

Thus, the aircraft crew selects the final approach based on the approachcharts they have in their possession, on the information given by theair-traffic controller and on the state of the on-board systems, as wellas on weather, which results in an important workload. With theincreasing use of GNSS (<<Global Navigation Satellite System>>technologies) such as the GPS constellation and the Galileoconstellation, as well as their increases such as the SBAS, GBAS or ABASsystems, as defined by the appendix 10 OACI (International CivilAviation Organisation) in the field of the aeronautic navigation and thearrival of new technologies as a MLS system, the number of possibleapproaches is still growing.

Within the scope of the present invention, the following precisionapproach procedures can for instance be taken into account:

-   -   an instrument approach procedure, relating to an instrument        landing system, for instance of the ILS (<<Instrument Landing        System>>) type, such as described for instance in patent        FR-2,852,685;    -   an instrument approach procedure, relating to a microwave        landing system, for instance of the MLS (<<Microwave Landing        System>>) type; and    -   an instrument approach procedure, relating to a GPS (<<Global        Positioning System>>) landing system of the GLS (<<GBAS Landing        System>>) type.

Moreover, a non precision approach procedure of the RNAV type can beflown with either the SLS (<<Satellite Landing System>>) or FLS (<<FMSLanding System>>) function. The FLS function is for instance describedin patents FR-2,852,683, FR-2,852,684 and FR-2,852,686.

The final approach selection thus requires from the crew to perform anumber of actions, the number of which grows, as the number of availableapproaches on a ground increases, which induces a growing workload.

The present invention aims to overcome such drawbacks. It relates to amethod for aiding the piloting of an aircraft during an approach finalphase, which allows the workload of the aircraft crew to be reduced andto bring at least a partial automation and thus to favourably act on theaircraft safety.

To this end, according to the invention, said method aids the pilotingof an aircraft during the approach final phase for a landing on anairport, said approach final phase being implemented according to one ofa plurality of different approaches, to each one of which a particulardecision height is associated, is remarkable in that:

-   -   a) means for allowing a member of the crew to select a landing        way of the airport, that will be used upon the landing are        provided;    -   b) among the possible approaches, one approach for landing on        the selected landing way, which is technically adapted to be        implemented by the aircraft, namely the one presenting the        lowest decision height, is automatically selected; and    -   c) the thus selected approach for the activation of an approach        which will effectively be implemented by the aircraft is used.

Thus, thanks to the invention, an approach among the possible approachesfor landing on a previously selected way is automatically selected. Thisallows for the workload of the crew to be considerably reduced duringthe approach phase and also to increase the safety at the aircraftlevel.

To perform such automatic selection, the characteristics of the existingapproaches that are contained in a database and more precisely of thosethat are likely to be implemented for the selected landing way are takeninto account. Advantageously, to check if an approach is technicallyadapted to be implemented, it is checked:

-   -   if means being likely to detect signals that have to be used        during this approach are available on board the aircraft and are        in operational condition; and    -   if such means suitably detect said signals.

The selection according to the invention is performed by taking intoaccount the decision height for each one of the concerned approaches. Inthe scope of the present invention, <<decision height>> means the heightto the ground, from which the decision has to be taken latest, upon adescent, to perform or to stop the landing phase. At the decisionheight, the crew of the aircraft has to visually acquire the landingway. In such a case, the landing is ended in visual mode, with a manualguiding. The final guiding can also be performed automatically. Incontrast, if at this decision height, the crew does not see the landingway, a go-around has to be performed so as to rise the aircraft up to asafety altitude.

The automatic selection implemented at step b) can be performed indifferent ways, including according to the taking into account or not ofa recommended approach by Air Traffic Control ATC.

Without any recommendation of the Air Traffic Control, or without anytaking into account of an existing recommendation, for instance twodifferent variations of implementation can be provided. In a firstvariation of implementation, at step b):

-   -   b1) from a database containing the characteristics of the        existing approaches, those that are associated to the selected        landing way are extracted;    -   b2) among these extracted approaches, the one presenting the        lowest decision height is selected; and    -   b3) it is checked if the approach selected at step b2) can be        technically implemented by the aircraft, and if so, this        approach is considered as representing said selected approach,        whereas on the contrary if not, said steps b2) and b3) are        repeated for the approach presenting the immediately higher        decision height,        these steps b2) and b3) being repeated in an ascending order of        decision height until a selected approach likely to be        implemented, representing then said selected approach is        obtained.

Furthermore, in a second variation of implementation, at step b):

-   -   from a database containing the characteristics of the existing        approaches are extracted those being associated to the selected        landing way;    -   among those extracted approaches, all those that can technically        be implemented by the aircraft are checked; and    -   among the extracted approaches likely to be implemented is        selected that presenting the lowest decision height.

Furthermore, by taking into account a recommendation from the airtraffic control, the automatic selection can also be implemented in twodifferent ways.

In a first variation of implementation, at step b):

-   -   means for receiving from an air-traffic controller a recommended        approach are provided;    -   from a database containing the characteristics of the existing        approaches, those that are associated to the selected landing        way are extracted and the approaches are sorted out by growing        decision height, placing the recommended approach overhead of        this sorting; and    -   in this sorting is selected the first approach likely to be        technically implemented by the aircraft.

Furthermore, in a second variation of implementation, at step b):

-   -   means for receiving from an air traffic controller a recommended        approach are provided;    -   from a database containing the characteristics of the existing        approaches are extracted those being associated to the selected        landing way;    -   among those extracted approaches, all those that can technically        be implemented by the aircraft are checked;    -   if the recommended approach can be technically implemented, this        latter is selected;    -   otherwise, among the extracted approaches likely to be        implemented is selected that presenting the lowest decision        height.

Furthermore, the activation implemented at step c) can also be performedin different ways, for instance:

-   -   by automatically activating the approach selected at step b);    -   by presenting the approach selected at step b) to a crew member        of the aircraft, and by providing means allowing this crew        member to manually validate this approach; and    -   by presenting approaches to a crew member of the aircraft, and        by envisaging means allowing this crew member to select manually        an approach.

Furthermore, if two approaches can both be technically implemented andpresent the same decision height, the selection of the approach can bebased:

-   -   either on an arbitrary choice decided by the airline; or    -   on a theoretical availability relating to the approach type; or    -   on a piece of information indicating that one of those two        approaches is not operating.

Furthermore, at step b), a sorting can be performed according to,moreover, at least one of the following criteria:

-   -   the type of approach: precision approach, non precision        approach;    -   the approach means: MLS, ILS, GLS, SLS, FLS.

The present invention also relates to a device for aiding the pilotingof an aircraft, particularly a transport aircraft, during an approachfinal phase for the landing on an airport.

According to this invention, said device comprises:

-   -   means for allowing a crew member of the aircraft to select a        landing way of the airport that will be used during the landing;    -   means for selecting automatically, amongst the possible        approaches, one approach for landing on said selected landing        way, which is technically adapted to be implemented by the        aircraft, that is the one presenting the lowest decision height;        and    -   means for using the thus selected approach for activating one        approach which will effectively be implemented by the aircraft.

The present invention can also relate to an aircraft, in particular atransport airplane, comprising a device for aiding the piloting, such asthat above-mentioned.

The sole FIGURE of the appended drawing will better explain how thisinvention could be implemented.

This sole FIGURE is the block diagram of a device for aiding thepiloting of an aircraft, according to the invention.

The device 1 according to the invention and schematically represented onthe FIG. aims at aiding the piloting of an aircraft (not illustrated),particularly a transport aircraft during the approach final phase for alanding on an airport.

This approach final phase has to be implemented, in a usual way,according to one of a plurality of different approaches, to each one ofwhich is associated a particular decision height. <<Decision height>>means the height to the ground, from which the decision has to be takenlatest (upon a descent) to continue the procedure and perform a landingor to stop the landing phase. From this decision height, the landing isperformed manually by the pilot who sees the landing way. The finalguiding can also be performed automatically. During a precision approachwith instruments for instance, flight meteorological conditions withinstruments are switched to visual flight meteorological conditions, atsaid decision height (or above such decision height).

According to the invention, said device 1 which is on board theaircraft, comprises:

-   -   means 2, for instance a keyboard and/or a mouse associated to a        monitor that allow a crew member of the aircraft to select a        landing way of the airport, that is the way that the crew wants        to use upon the landing;    -   means 3 for automatically selecting, amongst the possible        approaches, one approach for the landing on said selected        landing way (with the aid of the means 2), that is generally an        approach:        -   which presents the lowest decision height; and        -   which is technically likely to be implemented by the            aircraft; and    -   means 4 for using the thus selected approach for activating one        approach which will effectively be implemented by the aircraft,        as indicated hereinafter.

Thus, the means 3 of the device 1 according to the inventionautomatically select one approach among the possible approaches, for alanding on a way previously selected by a crew member. This allows toconsiderably reduce the workload of the crew during the approach phaseand to increase the safety at the aircraft level.

According to the invention, said means 3 comprise at least:

-   -   means 5, for instance a flight management system of the FMS        type, which are intended to perform the automatic selection by        being in relationship, as illustrated, by a link 6, with means        7; and    -   said means 7, for instance a multimodal receiver of the MMR        (<<Multi-Mode Receiver>>) mode, which are able to check if one        given approach is technically likely to be implemented by the        aircraft.

To be sure that one approach is technically likely to be implemented,said means 7 check for instance:

-   -   if usual detection means likely to detect signals which have to        be used during this approach, are available on board the        aircraft and are in operational condition; and    -   if these detection means suitably detect said signals, that is,        particularly that said signals are effectively transmitted.

Said means 5 comprise for instance one database 8, either embedded orindependent, which contains the characteristics of the existingapproaches, that is particularly:

-   -   the type of approach: precision approach (flight with        instruments) or non precision approach;    -   the usual guiding means used for the approach: MLS, ILS, GLS,        SLS, FLS ; and    -   the associated decision height, that is the minimal height        allowed to take the landing decision.

The device 1 can also comprise an auxiliary database containing lists ofthe landing ways available on airports. Thus, a crew member can select adestination airport, for instance with the aid of means 2. The device 1thus proposes to the crew, for instance with the aid of the means 3, allthe landing ways being available on this destination airport so thatthis crew member can select, with the aid of the means 2, the landingway which will be effectively used for landing.

The automatic selection implemented by the means 3 can be performed ondifferent ways whether an approach recommended by the air-trafficcontrol is taken into account or not. In a first embodiment, for which arecommended approach (being specified hereunder) is not taken intoaccount, two variations of different implementations are provided.

In a first variation of implementation of this first embodiment:

-   -   the means 5 extract from the database 8 the approaches that are        associated to the landing way selected by a crew member by the        aid of the means 2;    -   said means 5 select amongst the thus extracted approaches, that        which presents the lowest decision height; and    -   the means 7 check if the approach which presents the lowest        decision height is technically likely to be implemented.

To this end, said means 7 thus check:

-   -   if detection means likely to detect signals which have to be        used during this approach, are available on board the aircraft;        and    -   if the detection means suitably detect said signals.

If this approach cannot be implemented, the means 5 are aware of thatand select the approach having the decision height immediately above thepreceding one, then ask again the means 7 concerning the capacity toimplement this approach by aircraft, these operations being repeated upto obtaining one approach which is likely to be technically implementedby the aircraft.

Furthermore, in a second variation of implementation of this firstembodiment:

-   -   the means 5 extract from the database 8 all the approaches which        are associated to the selected landing way (with the aid of the        means 2) and transmit them to the means 7;    -   said means 7 check, among such extracted approaches, all those        which can be technically implemented by the aircraft and inform        the means 5 about it; and    -   said means 5 select, among such extracted approaches those which        are likely to be implemented, that which present the lowest        decision height.

Furthermore, in a second embodiment, one approach recommended by the airtraffic control is taken into account. In particular, the air trafficcontrol can recommend one approach using the most efficient approach aidmeans installed on the aircraft or an approach which is availableaccording to planned maintenance actions and traffic, as well asmeteorology.

In the scope of the present invention, this recommended approach can beacquired of different ways by the device 1, that is for instance:

-   -   by an electronic communication between the ground and the        aircraft, which can be automatically taken into account, via        usual means 9 which are linked to said means 5 via a link 10; or    -   by a manual entry through the crew, by means of appropriate        means, in particular said means 2 which are linked via a link 11        to said means 5; or    -   by the validation through the crew with appropriate means (for        instance said means 2) of the reception of a piece of        information from the ground.

In a first variation of the implementation of this second embodiment:

-   -   the means 5 extract from the database 8 the approaches which are        associated to the selected landing way and sort the approaches        by growing precision height by placing the recommended approach,        received from one of the above mentioned ways, overhead of a        list showing this sorting; and    -   the means 7 check if the first approach of this list        (recommended approach) is likely to be implemented.

If so, the recommended approach shows the selected approach, and if not:

-   -   the means 7 check if the second approach of this list is likely        to be implemented; and    -   if this approach cannot be implemented, means 5 are aware of it        and select the following approach in the list, then ask again        the means 7 about the capacity to implement this approach by        aircraft, such operations being repeated up to obtaining an        approach which is likely to be technically implemented by the        aircraft.

Furthermore, in a second variation of implementation of this secondembodiment:

-   -   the means 5 extract from the database 8 the approaches that are        associated to the selected landing way and inform the means 7        about it; and    -   the means 7 check among these extracted approaches, all those        which can be technically implemented by the aircraft and inform        the means 5 about it; and    -   the means 5 select as an approach:        -   this latter, if the recommended approach can be technically            implemented;        -   otherwise, the one among the extracted approaches likely to            be implemented presenting the lowest decision height.

Furthermore, whatever the embodiment considered, if two approaches canboth be technically implemented on board the aircraft and present thesame decision height, the selection of one of the approaches can bebased:

-   -   either on an arbitrary choice decided by the airline (through a        priority order defined by an AMI (Airline Modifiable        Information) parameter; or    -   on a theoretical availability relating to the approach type; or    -   on a piece of information, preferably of the NOTAM (NOtification        To Air Men) type, via a ground-board communication or a crew        manual entry, indicating that one of both approaches is not in        operation.

Furthermore, in addition to a sorting according to the decision height,the means 5 can also perform a sorting according to at least one of thefollowing criteria:

-   -   the type of approach: precision approach, non precision        approach;    -   the approach means: MLS, ILS, GLS, SLS, FLS.

It should be noticed that the sorting mode to be used can be determinedby the airline for instance thanks to an AMI parameter.

The approach selected by the means 3 can also be transmitted by themeans 5 (via a link 13) to display means 12 which are intended topresent this piece of information to the members of the aircraft crew.

Furthermore, in the scope of the present invention, the activation of anapproach can be performed on different ways. The activation of anapproach results in the performing of different actions, and includingthe entry of data concerning the approach in the flight managementsystem so that it can help with the management of this approach,including allowing different systems of the aircraft participating tothe approach to coordinate.

It should be noticed that the effective implementation of an activatedapproach, that is the piloting of the aircraft in accordance with thisapproach, is performed in a usual way. As a result, it is not furtherillustrated in the present description.

The means 4 of the device 1 according to the invention can be formed inorder to perform different activation types.

The activation can for instance be automatically effected. In this firstimplementation, the usual activation means 14 intended for theactivation receive from said means 5, through a link 15, the approachbeing automatically selected by such means 5, and said means 14automatically activate this selected approach. This first implementationallows highly reduce the crew workload, since the selection and theactivation are both automatically performed.

It is also contemplated to perform the activation by crew validation,with validation means 16, linked by a link 17 to said means 14. In thissecond embodiment, several logics can be defined, that is:

-   -   the device 1 proposes the selected approach, for instance on the        displaying means 12. The pilot can accept or refuse it, through        the means 16. If he refuses it, the device 1 submits a new        proposal to the pilot; or    -   the device 1 proposes the selected approach by the means 5, for        instance on the displaying means 12. The pilot can accept or        refuse this proposal with the aid of the means 16. If he refuses        it, the device 1 proposes all the approaches likely to be        implemented, classified by growing decision height; or    -   the device 1 proposes all the approaches likely to be        implemented, for instance on the displaying means 12, classified        by growing decision height (with the overhead recommended        approach, the case being), letting the pilot decide and activate        the approach he desires, for instance with the help of said        means 16.

When several approaches are proposed to the crew, they are presented onmonitors, in particular from said displaying means 12, and arepreferably sorted according to a sorting order selected by the airline,through for instance an AMI parameter. It is also contemplated, inparticular for airports having a great number of different approaches,to gather the proposed approaches by type (precision approach, nonprecision approach) or by approach means (MLS, ILS, GLS, SLS, FLS, . . .).

In this second embodiment, the final decision concerning the choice ofthe approach to be activated always pertains to the crew of theaircraft, which can thus activate a different approach from thatselected by the means 3.

It should be noticed that the activation of the approach is generallyperformed in the flight management system of the aircraft, so that saidmeans 14 and 16 are part of said means 5.

1. A method for aiding the piloting of an aircraft during an approachfinal phase for a landing on an airport, said approach final phase beingimplemented according to one of a plurality of different approaches, toeach one of which is associated one particular decision height, a methodwherein: a) means allowing a crew member to select a landing way of theairport, that will be used during the landing are provided; b) amongstthe possible approaches, an approach for the landing on said selectedlanding way is automatically selected, that is generally one approach:which presents the lowest decision height; and which is technicallylikely to be implemented by the aircraft, by checking if detection meanslikely to detect signals that have to be used during this approach, areavailable on board the aircraft, and if these detection means suitablydetect said signals; and c) the thus selected approach for theactivation of an approach which will effectively be implemented by theaircraft is used.
 2. The method according to claim 1, characterized inthat, at step b): b1) from a database (8) containing the characteristicsof the existing approaches, those that are associated to the selectedlanding way are selected; b2) among these extracted approaches, the onepresenting the lowest decision height is selected; and b3) it is checkedif the approach selected at step b2) can be technically implemented bythe aircraft, and if so, this approach is considered to represent saidselected approach, while on the contrary if not, said steps b2) and b3)are repeated for the approach presenting the immediately higher decisionheight, these steps b2) and b3) being repeated in an ascending order ofdecision height until a selected approach likely to be implemented,representing then said selected approach is obtained.
 3. The methodaccording to claim 1, characterized in that, at step b): from a database(8) containing the characteristics of the existing approaches, thosethat are associated to the selected landing way are selected; amongstthese extracted approaches, all those that can technically beimplemented by the aircraft are checked and amongst the extractedapproaches likely to be implemented is selected that presenting thelowest decision height.
 4. The method according to claim 1,characterized in that, at step b): means for receiving from an airtraffic controller a recommended approach are provided; from a database(8) containing the characteristics of the existing approaches, thosebeing associated to the selected landing way are extracted and theapproaches are sorted by growing decision height, by placing therecommended approach overhead of this sorting; and in this sorting isselected the first approach likely to be technically implemented by theaircraft.
 5. The method according to claim 1, characterized in that, atstep b): means for receiving from an air traffic controller arecommended approach are provided; from a database (8) containing thecharacteristics of the existing approaches, those that are associated tothe selected landing way are selected; among these extracted approaches,all those that can technically be implemented by the aircraft arechecked; if the recommended approach can be technically implemented,this latter is selected; otherwise, among these extracted approacheslikely to be implemented is selected that presenting the lowest decisionheight.
 6. The method according to claim 1, characterized in that atstep c), the approach selected at step b) is automatically activated. 7.The method according to claim 1, characterized in that at step c), theapproach selected at step b) is presented to a member of the aircraftcrew, and means allowing the crew member to manually validate thisapproach are provided.
 8. The method according to claim 1, characterizedin that at step c), approaches are presented to a member of the aircraftcrew, and means allowing this crew member to manually select an approachare provided.
 9. The method according to claim 1, characterized in that,at step b), a sorting is performed according to at least one of thefollowing criteria: the type of approach; the approach means.
 10. Themethod according to claim 1, characterized in that, to check if anapproach is technically likely to be implemented, it is checked: if themeans likely to detect signals that have to be used during this approachare available on board the aircraft and are in an operational condition;and if such means suitably detect said signals.
 11. A device for aidingthe piloting of an aircraft during an approach final phase for a landingon an airport, said approach final phase being implemented according toone of a plurality of different approaches, to each one of which isassociated a particular decision height, said device (1) comprising:means (2) allowing a crew member to select a landing way of the airport,that will be used upon landing; means (3) for automatically selectingamong the possible approaches, an approach for the landing on saidselected landing way, that is generally an approach: which istechnically likely to be implemented by the aircraft; and which presentsthe lowest decision height, said means (3) comprising means (7) to checkif the detection means likely to detect signals that have to be usedduring this approach, are available on board the aircraft and if thesedetection means suitably detect said signals; and means (4) for usingthe thus selected approach for activating one approach which willeffectively be implemented by the aircraft.